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Cleanup of Packet::createFirstLayer #1981

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Merged
merged 8 commits into from
Oct 10, 2025
+61 −49
Merged

Cleanup of Packet::createFirstLayer #1981

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d2f1c1b
Refactor if else chain to a switch case.
Dimi1010 Sep 29, 2025
fa250b1
Refactor branches to only return on successful parse. Failed parses a…
Dimi1010 Sep 29, 2025
bc4512a
Fix warnings about default case.
Dimi1010 Sep 30, 2025
82bc23a
Merge branch 'dev' into refactor/create-first-layer-cleanup
Dimi1010 Sep 30, 2025
52e2fe4
Merge remote-tracking branch 'upstream/dev' into refactor/create-firs…
Dimi1010 Oct 9, 2025
fe0ee61
Merge branch 'dev' into refactor/create-first-layer-cleanup
Dimi1010 Oct 10, 2025
4c147af
Removed else.
Dimi1010 Oct 10, 2025
5c6d14d
Moved null loopback validity check to isDataValid.
Dimi1010 Oct 10, 2025
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9 changes: 9 additions & 0 deletions Packet++/header/NullLoopbackLayer.h
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Original file line number Diff line number Diff line change
Expand Up @@ -78,5 +78,14 @@ namespace pcpp
{
return OsiModelDataLinkLayer;
}

/// @brief Check if the data passes minimal validity checks for Null/Loopback layer
/// @param data A pointer to the data
/// @param dataLen Size of the data in bytes
/// @return True if the data can represent a valid Null/Loopback layer, false otherwise
bool static isDataValid(const uint8_t* data, size_t dataLen)
{
return data != nullptr && dataLen >= sizeof(uint32_t);
}
};
} // namespace pcpp
101 changes: 52 additions & 49 deletions Packet++/src/Packet.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -739,87 +739,90 @@ namespace pcpp

const uint8_t* rawData = m_RawPacket->getRawData();

if (linkType == LINKTYPE_ETHERNET)
switch (linkType)
{
case LinkLayerType::LINKTYPE_ETHERNET:
{
if (EthLayer::isDataValid(rawData, rawDataLen))
{
return new EthLayer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
else if (EthDot3Layer::isDataValid(rawData, rawDataLen))
if (EthDot3Layer::isDataValid(rawData, rawDataLen))
{
return new EthDot3Layer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
else
{
return new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
break;
}
else if (linkType == LINKTYPE_LINUX_SLL)
case LinkLayerType::LINKTYPE_LINUX_SLL:
{
return new SllLayer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
else if (linkType == LINKTYPE_LINUX_SLL2 && Sll2Layer::isDataValid(rawData, rawDataLen))
case LinkLayerType::LINKTYPE_LINUX_SLL2:
{
return new Sll2Layer(const_cast<uint8_t*>(rawData), rawDataLen, this);
if (Sll2Layer::isDataValid(rawData, rawDataLen))
{
return new Sll2Layer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
break;
}
else if (linkType == LINKTYPE_NULL)
case LinkLayerType::LINKTYPE_NULL:
{
if (rawDataLen >= sizeof(uint32_t))
if (NullLoopbackLayer::isDataValid(rawData, rawDataLen))
{
return new NullLoopbackLayer(const_cast<uint8_t*>(rawData), rawDataLen, this);
else // rawDataLen is too small fir Null/Loopback
return new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
break;
}
else if (linkType == LINKTYPE_RAW || linkType == LINKTYPE_DLT_RAW1 || linkType == LINKTYPE_DLT_RAW2)
case LinkLayerType::LINKTYPE_RAW:
case LinkLayerType::LINKTYPE_DLT_RAW1:
case LinkLayerType::LINKTYPE_DLT_RAW2:
{
uint8_t ipVer = rawData[0] & 0xf0;
if (ipVer == 0x40)
if (ipVer == 0x40 && IPv4Layer::isDataValid(rawData, rawDataLen))
{
return IPv4Layer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(
new IPv4Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
return new IPv4Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
else if (ipVer == 0x60)
if (ipVer == 0x60 && IPv6Layer::isDataValid(rawData, rawDataLen))
{
return IPv6Layer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(
new IPv6Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
return new IPv6Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
else
break;
}
case LinkLayerType::LINKTYPE_IPV4:
{
if (IPv4Layer::isDataValid(rawData, rawDataLen))
{
return new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
return new IPv4Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
break;
}
else if (linkType == LINKTYPE_IPV4)
case LinkLayerType::LINKTYPE_IPV6:
{
return IPv4Layer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(new IPv4Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
if (IPv6Layer::isDataValid(rawData, rawDataLen))
{
return new IPv6Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this);
}
break;
}
else if (linkType == LINKTYPE_IPV6)
case LinkLayerType::LINKTYPE_NFLOG:
{
return IPv6Layer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(new IPv6Layer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
if (NflogLayer::isDataValid(rawData, rawDataLen))
{
return new NflogLayer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
break;
}
else if (linkType == LINKTYPE_NFLOG)
case LinkLayerType::LINKTYPE_C_HDLC:
{
return NflogLayer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(new NflogLayer(const_cast<uint8_t*>(rawData), rawDataLen, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
if (CiscoHdlcLayer::isDataValid(rawData, rawDataLen))
{
return new CiscoHdlcLayer(const_cast<uint8_t*>(rawData), rawDataLen, this);
}
break;
}
else if (linkType == LINKTYPE_C_HDLC)
{
return CiscoHdlcLayer::isDataValid(rawData, rawDataLen)
? static_cast<Layer*>(new CiscoHdlcLayer(const_cast<uint8_t*>(rawData), rawDataLen, this))
: static_cast<Layer*>(
new PayloadLayer(const_cast<uint8_t*>(rawData), rawDataLen, nullptr, this));
default:
// For all other link types, we don't have a specific layer. Just break and create a PayloadLayer
break;
}

// unknown link type
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